Moving an actuator as a ZProbe instead of the entire axis

[sotpurk]

Hello,
Would it be possible to map an actuator with a stepper as the Z probe with a switch on end rather than only deploying the Z probe and moving the entire Gantry up and down?
My gantry weighs almost 100 Kg so I'd like to minimize the Z motion as much as possible.
I was thinking something along the lines of:

1. Map the actuator as a separate axis and home the actuator zero with an end-stop on the actuator.
2. Move the extruder to the probe point and remap the Z to the actuator.
3. Retract the actuator till another switch or sensor (which is mapped as a Z probe) at the bottom end of it touches the bed and the actuator moves back up again.
4. Remap the Z back to the Z motors.

This seems doable as an alternative, but is there any inbuilt functionality in the Z probing setup that I could use here?

[dc42]

@sotpurk what do you want to use this Z probe for? Setting Z=0, or something more complicated such as mesh bed probing, bed tramming, or delta calibration?

[sotpurk]

@dc42 Setting Z=0, mesh probing, and bed leveling.
I tried the mentioned flow but the motors de-energize when changing assignments which results in lost steps.

[T3P3Tony]

@sotpurk I have moved this to the firmware wish listm, based on the conversation here:
https://forum.duet3d.com/topic/31694/keep-motors-energised-when-changing-assignment